Improvement in calculating-machines



v 2 sheets sheet 1. W. W. HOPKINS. Calculating-Machine.

Patented April 30, 1878..

2 Sheets-Sheet 2. W. W. HOPKINS. Calculating-Machine.

Patented April 30,1878.

INVENTOR AfTUBNEYS.

N-PSTERS, PHOTOLITNOGRAPNER, WASH No. 203,15I.

WITNESSES UNITED STATES PATENT OFFICE.

WILLIAM W. HOPKINS, OF THORNTOWN, INDIANA.

IMPROVEMENT IN CALCULATING-MACHINES.

Specification forming part of Letters Patent No. 203,151, dated April30, 1878; application filed March 14, 1578.

To all whom it may concern:

Be it known that I, WILLIAM W. HoPKINs, of Thorntown, in the county ofBoone and State of Indiana, have invented a new and ImprovedOalculating- Machine; and I do hereby declare that the following is afull, clear, and exact description of the same.

This invention is an improvement in the class of machines for use inadding and subtracting numbers, and in other mathematical operations. 1

The elements of the machine are, first, three series of notched wheels,mounted loose, and side by side, on three separate but parallelhorizontal shafts, and each of the wheels on two of the shafts beinginscribed on its periphery with the nine digits and the cipher (0);second, a corresponding series of endless chains having large links, andapplied to the said notched wheels, so as to travel when the latterrotate, and vice versa; third, a case or box in which the wheel-shaftshave their bearings, and having the nine digits and the cipher (0)inscribed in parallel rows on one of its sides, which I designate thecountingtablc.

The arrangement of the aforesaid elements is such that the chains travelover the inscribed side of the boxon lines coincident with the rows ofdigits. The several chains and rows of digits correspond to the units,hundreds, thousands, &c., columns of the figures to be added orsubtracted, 850.

The machine is operated by moving the chains successively downward thelength of the distance each number to be added, 850., is located on thecounting-table from the front edge thereof. When each chain has beenmoved downward for each number to be added or subtracted, &c., the sumor other numeriof about forty degrees, to facilitate the operation ofthe chains 0. Said top B is composed of the narrow upper part, having atransverse opening or slot, at, therein, and the board or table, onwhich are parallel rows of the nine digits and the cipher, the latterbeing placed at the bottom, and the digits succeeding in numericalorder.

The narrow front of the box A has a transverse slot, 12, similar to thetop part. A series of notched wheels, D, is mounted loose on a shaft, E,which is parallel and contiguous to the aforesaid upper slot on, and asimilar series of wheels, F, is similarly mounted on a shaft, G, whichis parallel to the lower slot 1). Each wheel in both upper and lowerseries is inscribed with the nine digits and the cipher, (0,) arrangedin regular numerical order on the periphery thereof; but the order isreversed that is to say, the digits 011 the wheels D of the upper seriesread numerically in one direction, and the digits on the wheels F of thelower series in the other direction, with reference to the table B. Theendless chains G pass around the coincident wheels D and F of theparallel shafts, and the latter are so arranged at top and bottom of theinclined table B that the visible portions of the chains extend acrossand lie in the same plane with the latter. The chains are composed oflarge links, through which the figures on the counting-table are plainlyvisible. A stop or rest bar, H, is located at the lower edge of thetable B, for a purpose hereinafter explained.

To carry ten between the units and tens column, or tens and hundreds,and so 011, I employ a third series of notched wheels, I,

which are mounted loose on a shaft, K, placed at a point intermediate ofthe shafts E and G, but parallel thereto. Each of these carryingwheelshas on one side a series of peripheral teeth, 0, that engage with thelinks ofits chain, and a single tooth, d, which projects from the otherside of the wheel, and at each revolir tion of the latter takes into oneof the links of the chain that passes around the next wheel on theright, and moves it the. length of one link on the table B-that is tosay, the tooth c of the wheel around which the units-chain passes takesinto and moves the chain, the tooth of the tens-wheel into thehundredschain, and so on.

By this arrangement and connection of parts the mathematical operationof carrying ten is performed automatically.

To put the machine in condition for operation, draw the chains 0downward until the cipher (0) appears through the slot at on all theupper wheels D. Then, to add numbers, proceed as follows: Use therighthand chain for all the figures in the units-column of numbers to beadded. Then use the second chain from the right-hand side for thetens-column, the third chain for the hundreds-column, the fourth chainfor thousands, and so on. The sum of the numbers added will appear onthe lower series of wheels F through the slot b-that is to say, supposethe numbers to be added are 13 and 12; first place a hook, pencil, orother suitable instrument in that link of the right-hand chain, throughwhich the figure 3 appears on the table B, and draw said chain downuntil the movement is arrested by the stop-bar E. Then place the pointof the pencil or other instrument in the link of the same chain throughwhich the figure 2 appears, and draw the chain down, as before. The sumof these numbers, to wit, 5, will then appear through the slot 7) on thefirst wheel F of the lower series. Next proceed in the same manner toadd the tens (1 and 1) by twice drawing down the second chain the lengthof one link; and the sum of the tens, to wit, 2, will appear through theslot 1) on the second wheel of the series, alongside the 5 on the firstwheel, so that 25 will thus be indicated as the sum of 12 and 13.

To subtract, adjust the machine so that the minuend will appear at theupper slot, use the chains the same as in adding, place the pointer onthe figures of the table which represent the subtrahend, and draw thechains down to the rest-bar. The remainder will ap pear at the upperslot where the minuend was.

To multiply, use the multiplicand the same as four numbers to be added.The product will appear at the lower slot.

To divide requires a different operation for each prime factor. Thus, todivide by 2 place dividend at upper slot and divide by short division,pulling the chain down the number of links the divisor is contained inthe dividend. The quotient will appear where dividend was.

To count interest, multiply principle by number or" days, and divide by6 for 6 per cent., or divide by 3 for 12 per cent., 850.

In place of the chains I may employ ordinary tapes or belts oftransparent material, having suitable marks to indicate spacescorresponding to the distance between the digits on the counting-table.In brief, while I prefer the chains, it is practicable to employ otherdevices in place of them.

My improved machine is distinguished by simplicity and cheapness ofconstruction and convenience of operation.

What I claim is- 1. In a calculating-machine, the combination of a boardor table inscribed with the nine digits, t :0 series of wheels inscribedwith the digits and the cipher, and a series of endless chains, orequivalents, passing around said wheels, in the manner described, tooperate as specified.

2. In a calculating-machine, the combination of the endless chainscomposed of open links, as specified, the notched wheels D and l andtheir parallel shafts, the inclined counting-table, and the box or caseprovided with slots a and b, all constructed and arranged as shown anddescribed.

WILLIAM W. HOPKINS.

Witnesses GEORGE THISTLETHWAIT. FRANK W. MAHAN.

